package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.conditions.query.QueryChainWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Resource
    private FollowMapper followMapper;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;

    @Override
    public Result isFollow(Long followUserId) {
        //获取当前登录用户id
        Long userId = UserHolder.getUser().getId();
        //1.查询当前用户是否已经关注了该用户
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count > 0);
    }

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //获取当前登录用户id
        Long userId = UserHolder.getUser().getId();
        //1.判断是关注还是取消关注
        if (isFollow) {
            //2.如果是关注，新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSave = save(follow);
            if (isSave) {
                String key = RedisConstants.FOLLOWS + userId;
                //将关注数据存入redis中
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        } else {
            //3.如果是取消关注，删除数据
            boolean isRemove = followMapper.remove(userId, followUserId);
            String key = RedisConstants.FOLLOWS + userId;
            //将关注数据从redis中删除
            if (isRemove) {
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result followCommons(Long id) {
        // 获取当前登录用户id
        Long userId = UserHolder.getUser().getId();
        // 查询共同关注的用户id
        Set<String> intersect = stringRedisTemplate.opsForSet()
                .intersect(RedisConstants.FOLLOWS + userId, RedisConstants.FOLLOWS + id);
        if (intersect == null || intersect.isEmpty()) {
            // 没有共同关注
            return Result.ok(Collections.emptyList());
        }
        // 根据id查询用户
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> userDTOS =userService.listByIds(ids).stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
